Methods and apparatus for foundation systems

ABSTRACT

Methods and apparatus for supporting a slab on a surface material according to various aspects of the present invention operate in conjunction with coupling a vertical support to the slab and removing a portion of the surface material from below the slab to form a void. A supplemental support is placed in the void between the surface material and the slab. The vertical support is removed from the slab.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. Nonprovisional Patent Application No. 11/966,413, filed Dec. 28, 2007, and incorporates the disclosure of such application by reference.

BACKGROUND OF INVENTION

Portions of the ground exhibit fluid characteristics. As a consequence, it is generally necessary to provide a solid surface, such as a slab, before construction of a building. While a slab may provide a more stable substructure than bare ground, the fluid properties of the ground may reduce the utility of the foundation and/or slab. Fluctuations in soil conditions, such as heaving and settling, may move the foundation, slab, and/or superstructure. Fluctuations may also cause structural stresses within and damage to the foundation, slab, and/or superstructure.

Prior art attempts to reduce or eliminate the adverse consequences of ground fluctuations beneath a foundation and/or slab have seen limited success. Many prior art attempts have been limited to removing or adding soil and/or structural supports only proximate the edges of a foundation. Where structural stress has been present in areas not proximate the edges of a foundation, prior art solutions have involved removing and rebuilding large portions of a building or foundation. Other prior art attempts have focused on pumping chemicals into the ground to modify the expansion properties of the ground, or placing heavy weights on the foundation and/or slab. These prior art solutions have had limited success and have been costly, and have sometimes resulted in further foundational cracks or damage.

SUMMARY OF THE INVENTION

Method and apparatus for supporting a foundation and/or slab on a surface material according to various aspects of the present invention operate in conjunction with coupling a vertical support to the foundation and removing a portion of the surface material from below the foundation to form a void. A supplemental support is placed in the void between the surface material and the foundation. The vertical support is removed from the foundation.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of the present invention may be derived by referring to the detailed description and claims when considered in connection with the following illustrative figures. In the following figures, like reference numbers refer to similar elements and steps throughout the figures.

FIG. 1 is a cross-sectional view of a foundation on soil.

FIG. 2 is a top view of one embodiment for realigning a foundation on soil having heterogeneous soil pressures.

FIG. 3 is a flow diagram representing a process for adjusting an existing foundation.

FIG. 4 is a cross-sectional view of a foundation on soil with a vertical support.

FIG. 5 is a cross-sectional view of a foundation on soil with a hole formed in the foundation.

FIG. 6 a top view of one embodiment for finishing a realigned foundation.

FIG. 7 is a cross-sectional view of a foundation on soil with supplemental supports.

FIG. 8 is a cross-sectional view of a foundation on soil with a patched hole over the supplemental supports.

Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present invention may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware or software components configured to perform the specified functions and achieve the various results. For example, the present invention may employ various tools, apparatus, and systems for formation and repair of foundations, e.g., machinery, jacks, supports, measurement devices, manometers, helical piers, bar joists, slabs, blocks, grout, drilling and/or sawing equipment, filler materials, cement, reinforcing materials, patching materials, weights, and the like, which may carry out a variety of functions. The present invention may also employ various processing steps and design considerations. In addition, the present invention may be practiced in conjunction with any number of construction applications and with any other foundation formation or repair method or apparatus, and the system described is merely one exemplary application for the invention. Further, the present invention may employ any number of conventional techniques for construction technologies, such as raising a foundation, removing a portion of the foundation, excavating soil, putting supports in place, backfilling soil and/or other filler materials, patching removed portions of the foundation, reinforcing the foundation, lowering the foundation, applying temporary or permanent weight to the foundation, and the like.

Various representative implementations of the present invention may be applied to any system for installation, repair, and/or adjustment of foundations. Certain representative implementations may include, for example, preparing and installing a foundation before or during new home or building construction, adjusting a foundation before or during new home or building construction, repairing or adjusting an existing or old foundation after home or building construction, etc.

Referring now to FIG. 1, a foundation 100 may comprise a slab 102 positioned above soil 103. The soil 103 may exhibit heterogeneous conditions, such as different soil 103 pressures. For example, referring to FIG. 2, manometer readings representing different soil pressures may be mapped using isometric lines for an area under the slab 102. Different soil pressures may tend to move or deform the slab 102 due to soil 103 movement below the slab 102. Such movement can cause external and internal cracks in a building.

To reduce the effects of soil 103 movement on the slab 102, the slab 102 may be installed or adjusted by excavating soil 103 below the slab 102 and adjusting the slab 102 to a desired position. Supplemental supports may then be installed below the raised slab 102. To facilitate the removal of soil 103 and/or insertion of the supplemental supports, the slab 102 may be coupled to one or more vertical supports to support and/or adjust the position of the slab 102. The adjusted slab 102 may be positioned onto the supplemental supports to achieve a substantially flat foundation 100. The vertical supports may be removed and the slab 102 may rest upon the supplemental supports. Any void below the adjusted slab 102 may be at least partially filled with an insulating material, such as a waterproofing agent and/or foam, to reduce the likelihood of damage to the foundation 100 as a consequence of the void. Additionally, a protective wall 108 may be installed around the perimeter of the slab 102 to prevent material from accumulating below the slab 102.

The slab 102 may comprise a base for a building or other structure formed of any appropriate materials, such as post-tension concrete, poured concrete, cellulose, and/or rebar. The slab 102 may be configured according to various design considerations, including the properties of the intended superstructure, the properties of the soil 103, and/or the like. In the present embodiment, the slab 102 comprises a slab for a building. Reduced utility in the slab 102 due to changing soil 103 conditions may take the form of cracks in the slab 102, cracks in the superstructure connected to the slab 102, misalignment of the slab 102 and/or superstructure, or other structural issues.

The slab 102 may be adjusted according to various aspects of the present invention, such as by identifying soil 103 to be excavated, excavating the relevant soil 103, installing one or more vertical supports, coupling the slab 102 to one or more vertical supports, adjusting the elevation and/or the tilt of the slab 102, and/or the like. Referring to FIG. 3, in one embodiment, the vertical supports are installed (302) and soil 103 to be excavated is accessed (304). A selected portion of soil 103 is excavated (306) and the slab 102 is adjusted to a desired position (308). At least one supplemental support may be installed between the slab 102 and the ground below the slab 102. The slab 102 is secured to or rested upon the supplemental support 206 (310) and any finishing operations are performed (312).

The soil 103 below and/or around the slab 102 may be evaluated for stability according to various methods and techniques. For example, the soil 103 may be analyzed prior to construction. Analysis that was done prior to construction may apply to the present soil 103 conditions, as in the case of substantially stable soils. Analysis done prior to construction, however, may no longer apply to present soil 103 conditions, as in the case of substantially unstable soils. Accordingly, equipment such as soil borings, manometers, ultrasound equipment, subterranean imaging systems, and/or the tike may be employed to determine present soil 103 conditions. For example, in the case of a manometer, the soil 103 may be tested to determine areas of high and low pressure below the soil 103. Based on the test results, the source of damage or potential damage to the foundation 100 may be determined and excavation may proceed accordingly.

The slab 102 may be stabilized to permit the excavation. The slab 102 may be stabilized in any appropriate manner to inhibit unwanted movement. For example, referring to FIGS. 1 and 4, vertical supports 106 may be installed around portions or all of the perimeter of the slab 102. The vertical supports 106 may be selected and installed using any appropriate criteria and/or techniques. In the present embodiment, the vertical supports 106 may at least partially support the slab 102 above the soil 103. The vertical supports 106 may comprise various materials, embodiments, and geometries, such as helical piers or hydraulic piers. The vertical supports 106 may be driven into the ground to a depth at which the soil 103 fluctuations are limited. For example, a helical pier 510 may be installed via rotation of the helical pier 510 according to an inclined plane portion of the helical pier 510. As another example, a post may be installed with an axial force as by a hammer. As yet another example, a vertical support 106 may be formed within the ground as in the case of a concrete and rebar pillar.

The vertical supports 106 may be coupled to the slab 102 to accommodate adjustment of the slab 102 relative to the substantially fixed portion of the vertical supports 106. Referring again to FIG. 2, in situations where the slab 102 is disposed proximate to other slabs 102, 114, 116, the vertical supports 106 may be installed through and/or around the other portions 102, 114, 116 of the slab 102. In addition, the slab 102 may be removably or permanently fixed to the vertical supports 106. In one embodiment a hole, is drilled in the slab 102 and a stem is doweled to the slab 102 through the hole such that the stem facilitates support and movement of the slab 102 by the vertical support 106. In one such embodiment, the dowel comprises steel rebar from ⅛ inch to 3 inches in diameter, such as ½ inch to 1 inch in diameter.

The vertical supports 106 may be installed at any appropriate time, such as before or after excavation. For example, the vertical supports 106 may be installed and attached to the slab 102 before excavation to support the slab 102 as soil 103 is removed from below the slab 102. Alternatively, the vertical supports 106 may be installed and attached to the slab 102 during or after excavation to adjust and/or maintain the position of the slab 102.

The soil 103 to be excavated may be accessed to facilitate removal or adjustment of the soil 103. Access may be gained using various methods and/or techniques, including removing a section 104 of the slab 102 and/or excavating around the perimeter of the slab 102 to access the soil 103 below the slab 102. Removal of a section 104 may be desirable in scenarios in which the perimeter of the slab 102 is not available for excavation, as in the case of row houses. Alternatively, excavation around the perimeter of the slab 102 may be desirable in scenarios in which the slab 102 is not available for removal of a section 104, as in the case of an exceedingly brittle and/or exceedingly thick slab 102, or other situations in which removing a section may be impractical.

A section 104 may be removed using various methods and/or techniques. For example, referring to FIG. 5, a section 104 of the slab 102 may be removed using equipment to drill and/or cut concrete or other slab 102 material. Alternatively, for a slab 102 comprised of a different material, such as wood, a corresponding set of equipment may be employed. In one embodiment, the slab 102 comprises concrete and a saw is employed to cut and remove the section 104.

The removed section 104 may be configured according to any appropriate criteria, such as the area available in which to work without removing interior walls, proximity to other structures such as plumbing and electrical systems, and the thickness of the slab 102. For example, if the section of soil 103 to be removed 112 has been determined prior to removal of the section 104, the section 104 may have dimensions according to the section of soil 103 to be removed 112. As another example, if materials to patch the section have specified dimensions, the section 104 may have dimensions according to the specified dimensions. In one embodiment, the removed section 104 has dimensions of 5 feet by 5 feet, while in another embodiment the removed section has dimensions of 3 feet by 3 feet. The removed section 104 could be any other size or shape, however, according to the particular situation.

The soil 103 may be excavated to remove and/or adjust the soil 103. The soil 103 may be excavated in any appropriate manner, such as using high power compressor nozzles, potholing, and/or vacuum excavation. Soil 103 may be removed from any suitable area, such as via the perimeter of the slab 102 and/or through the removed section 104. The area of excavation 112 may extend directly below the removed section 104 and/or laterally 110 around the removed section 104 below the slab 102. Multiple sections 104 may be removed and soil 103 may also be excavated from multiple areas.

In the present embodiment, the soil 103 may be excavated through the removed sections 104 using a nondestructive removal process, such as water or air vacuum excavation. For example, high pressure air or water may be directed to the soil 103 to break up the soil 103. A powerful vacuum removes the loosened soil 103 and transports through the removed section 103 to a remote area, such as a holding tank, where the removed soil 103 may be stored for backfill or hauled away for disposal. The excavation system may also create small holes dig “slot trenches” to identify obstructions, such as existing utilities, and work around the obstructions without removing or damaging them.

The slab 102 may be adjusted to a desired position. For example, if expansive soil 103 has moved the slab 102, the slab 102 may be returned to its original position following excavation of the expansive soil 103. Any appropriate techniques may be applied to move the slab 102 into the desired position. In one embodiment, the vertical supports 106 attached to the slab 102 may be adjusted to raise or lower various portions of the slab 102. In addition, mass may be placed on the slab 102 to force the slab 102 downward, such as sandbags or concrete blocks.

In the present embodiment, one or more of the vertical supports 106 comprises an adjustable support 204 disposed between the slab 102 and the soil 103, such as a temporary adjustment jack to be removed at some point after the supplemental support 206 is put in place. The adjustable support 204 may support the slab 102 above the soil 103 and to facilitate movement of the slab 102 relative to the soil 103. The adjustable support 204 may be used to locally adjust the position of the slab 102, such as to raise or lower the slab 102 or to facilitate placement of a supplemental support 206. For example, the adjustable supports 206 may be adjusted to raise the slab 102 to facilitate placement of supplemental supports under the slab 102 or to move the slab 102 to a particular position. The adjustable supports 206 may also be adjusted to lower the slab 102 to a desired position and/or to rest the slab 102 on supplemental supports placed beneath the slab 102.

At least one supplemental support 206 may be disposed between the stab 102 and the soil 103, such as to support the slab 102 above the soil 103. The supplemental support 206 may comprise a structure, such as a preformed cement block, disposed between the soil 103 and the slab 102. The supplemental support 206 may be adapted and positioned to support, the slab 102 in position and/or reduce stresses within the stab 102 due to the weight of the slab 102. The supplemental support 206 may be driven into place through the soil 103 below the slab 102, placed directly below the slab 102 through a removed section 104 or via the perimeter of the stab 102, formed from a malleable material within the void, and/or the like.

In the present embodiment, the supplemental support 206 comprises a standard 8×8×16 concrete masonry unit (CMU). Referring to FIGS. 6 and 7, the supplemental support 206 may be placed in the void formed by the excavation of the soil 103, for example via the removed section 104. The supplemental support 206 rests on the soil 103 remaining below the slab 102, and is positioned below the slab 102 so that when the slab 102 is lowered, the slab 102 rests upon the supplemental support 206. Thus, the supplemental support 206 is adapted to support the slab 102 when the unstable soil 103 has been removed and adjustment of the slab 102 position is complete. Upon placement of the supplemental supports 206, the vertical supports 106 may be removed to allow the slab 102 to rest on the supplemental supports 206.

Voids between the soil 103 and the slab 102 may be filled, for example to inhibit moisture, provide insulation, or deter animals. For example, referring to FIG. 8, filler material 810, such as polyurethane foam, may be placed below the slab 102 in the void around the supplemental support 206. The filler material 810 may be adapted to distribute the mass of the slab 102 and superstructure as well. In various embodiments, the tiller material 810 may be compressible, such as a low density polyurethane foam, which allows the filler material 810 to at least partially absorb future soil 103 movement without transferring the movement to the slab 102. Any appropriate filler material 810 may be selected for example according to the particular environment or application. In one embodiment, the tiller material Bit) comprises a higher modulus compressible foam. In another embodiment, the filler material 810 comprises polyurethane foam balls, in yet another embodiment, the filler material 810 comprises a balloon or bladder containing a compressible foam, such as a polyurethane foam.

In addition, the foundation 100 may also include other protection against potentially damaging agents, such as water, frost, flora, and/or fauna. For example, a protective wall 108 may be installed at least partially along the perimeter of the adjusted slab 102, such as by digging a trench along and/or around the perimeter of the slab 102, at least partially lining the trench with a waterproofing material such as plastic, and at least partially filling the trench as with fluid cement, soil 103, and/or concrete blocks. In one embodiment, the protective wall 108 comprises a 5-foot deep trench lined with 30 mil plastic and backfilled with cement. The dimensions, geometry, and materials comprising a protective wall 108 may relate to the likely properties of the potentially damaging agents.

Any removed section 104 may he patched (312) to return the integrity of the slab 102, such as for structural and/or aesthetic purposes. The slab 102 may be patched in any appropriate manner, such as using conventional slab 102 repair materials and techniques. For example, within the removed section 104, a coupling material 208 may be employed to couple the slab 102 to at least one piece of patching material 212. The coupling material 208 may comprise a fibrous material, such as carbon fiber laminate. The patching material 212 may comprise pre-formed cement tile like that sold under the trade name WonderBoard. The patching material 212 may be reinforced using various reinforcing members 210, such as rebar. Above the patching material 212, a smoothing layer of material, such as grout and/or cement, may be poured to provide a substantially smooth horizontal surface to the finished slab 102.

For example, referring again to FIG. 6, the slab removal area 200 may comprise a perimeter 202 defining the removed section 104. The perimeter 202 may be modified to accommodate a preformed material, such as concrete sheet material. Alternatively, a preformed material may be modified to fit within the perimeter 202 of the removed section 104. A preformed material may be doweled to the slab 102 and/or otherwise attached. In addition to patching the removed section 104, finishing operations for the adjusted and/or patched slab 102 may include patching cracks in the slab 102 and/or the superstructure. Any appropriate techniques and materials may be used during finishing, such as for stitching, laminating, grouting, and/or the like. In one embodiment the patching material 212 comprises carbon fiber laminate stitch (which is sanded rough on one end) engaging the slab 102, ½-inch WonderBoard, and #4 rebar.

To the extent that the soil 103 conditions impair the utility of the foundation 100, the present methods and apparatus may be employed to improve the utility of the foundation 100. Potential and/or actual structural problems due to heaving of the foundation 100 may be mitigated without the need to remove the superstructure. Additionally, a foundation 100 may be adjusted to a desired elevation.

The particular implementations shown and described are illustrative of the invention and its best mode and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and/or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may be present in a practical system.

In the foregoing description, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth herein. The description and figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the generic embodiments described herein and their legal equivalents rather than by merely the specific examples described above, for example, the steps recited in any method or process embodiment may be executed in any order and are not limited to the explicit order presented in the specific examples. Additionally, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the specific examples.

Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problems or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components.

As used herein, the terms “comprises”, “comprising”, or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.

The present invention has been described above with reference to a preferred embodiment. However, changes and modifications may be made to the preferred embodiment without departing from the scope of the present invention. These and other changes or modifications are intended to be included within the scope of the present invention, as expressed in the following claims. 

1. An apparatus for supporting a foundation on soil, comprising: a vertical support coupled to the foundation; a supplemental support abutting the foundation and the soil; a patching material disposed within a hole formed in the foundation proximate the supplemental support, wherein the supplemental support is disposed within a void between the foundation and the soil created by removal of the soil through the hole.
 2. An apparatus according to claim 1, wherein the vertical support is selectively coupled to the foundation and to the soil below the foundation.
 3. An apparatus according to claim 2, wherein the vertical support comprises a helical pier.
 4. An apparatus according to claim 2, wherein the vertical support comprises a vertically extendable support.
 5. An apparatus according to claim 1, further comprising a filler material between the foundation and the soil proximate the supplemental support, wherein the filler material is disposed within the void between the foundation and the soil created by removal of the soil through the hole.
 6. An apparatus according to claim 5, wherein the filler material comprises a compressible material.
 7. An apparatus according to claim 1, wherein the void between the foundation and the soil is created by vacuum excavating the soil.
 8. A method for supporting a foundation on a surface material, comprising: coupling a vertical support to the slab; removing a portion of the surface material from below the slab to form a void; placing a supplemental support in the void between the surface material and the slab; and removing the vertical support.
 9. A method according to claim 0, further comprising: creating a hole in the slab; and patching the hole in the slab with a patching material coupled to the slab, wherein removing the portion of the surface material from below the slab comprises removing the portion of the surface material through the hole.
 10. A method according to claim 9, wherein removing the portion of the surface material from below the slab comprises vacuum excavating the portion of the surface material.
 11. A method according to claim 0, further comprising lowering the slab until the slab contacts the supplemental support.
 12. A method according to claim 0, further comprising disposing a filler material within the void.
 13. A method according to claim 12, wherein the tiller material comprises a compressible filter material.
 14. A method according to claim 0, wherein the vertical support comprises a helical pier.
 15. A method according to claim 0, wherein the vertical support comprises a vertically extendable support.
 16. A method for supporting a building slab on soil, comprising: attaching adjustable piers to the slab; creating a hole in the slab; removing a portion of the soil from below the slab through the hole to form a void; placing a supplemental support on the soil in the void; lowering the slab so that the slab rests upon the supplemental support; patching the hole with a patching material; and removing the piers.
 17. A method according to claim 16, wherein the vertical support comprises a helical pier.
 18. A method according to claim 16, wherein the vertical support comprises a vertically extendable support.
 19. A method according to claim 16, further comprising disposing a tiller material in the void.
 20. A method according to claim 19, wherein the filler material comprises a compressible material.
 21. A method according to claim 16, wherein removing the portion of the soil comprises vacuum excavating the portion of the soil. 